Visser L G, Seijmonsbergen E, Nibbering P H, van den Broek P J, van Furth R
Department of Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands.
Infect Immun. 1999 Mar;67(3):1245-50. doi: 10.1128/IAI.67.3.1245-1250.1999.
The virulence plasmid-borne genes encoding Yersinia adhesin A (YadA) and several Yersinia secreted proteins (Yops) are involved in the inhibition of phagocytosis and killing of Yersinia enterocolitica by human granulocytes. One of these Yops, YopH, dephosphorylates multiple tyrosine-phosphorylated proteins in eukaryotic cells and is involved in the inhibition of phagocytosis of Y. enterocolitica by human granulocytes. We investigated whether antibody- and complement-opsonized plasmid-bearing (pYV+) Y. enterocolitica inhibits O2- production by human granulocytes in response to various stimuli and whether YopH is involved. Granulocytes were preincubated with mutant strains unable to express YadA or to secrete Yops or YopH. O2- production by granulocytes during stimulation was assessed by measuring the reduction of ferricytochrome c. PYV+ Y. enterocolitica inhibited O2- production by granulocytes incubated with opsonized Y. enterocolitica or N-formyl-Met-Leu-Phe (f-MLP). This inhibitory effect mediated by pYV did not affect receptor-independent O2- production by granulocytes in response to phorbol myristate acetate, indicating that NADPH activity remained unaffected after activation of protein kinase C. The inhibition of f-MLP-induced O2- production by granulocytes depends on the secretion of Yops and not on the expression of YadA. Insertional inactivation of the yopH gene abrogated the inhibition of phagocytosis of antibody- and complement-opsonized Y. enterocolitica by human granulocytes but not of the f-MLP-induced O2- production by granulocytes or tyrosine phosphorylation of granulocyte proteins. These findings suggest that the specific targets for YopH are not present in f-MLP receptor-linked signal transduction and that other Yop-mediated mechanisms are involved.
编码耶尔森菌粘附素A（YadA）和几种耶尔森菌分泌蛋白（Yops）的毒力质粒携带基因参与抑制人类粒细胞对小肠结肠炎耶尔森菌的吞噬作用和杀伤作用。这些Yops之一，YopH，可使真核细胞中多种酪氨酸磷酸化蛋白去磷酸化，并参与抑制人类粒细胞对小肠结肠炎耶尔森菌的吞噬作用。我们研究了抗体和补体调理的携带质粒（pYV+）的小肠结肠炎耶尔森菌是否会抑制人类粒细胞在受到各种刺激时产生O2-，以及YopH是否参与其中。粒细胞先与无法表达YadA或分泌Yops或YopH的突变菌株预孵育。通过测量高铁细胞色素c的还原情况来评估刺激过程中粒细胞产生O2-的情况。pYV+小肠结肠炎耶尔森菌可抑制与调理后的小肠结肠炎耶尔森菌或N-甲酰甲硫氨酰亮氨酰苯丙氨酸（f-MLP）孵育的粒细胞产生O2-。pYV介导的这种抑制作用并不影响粒细胞对佛波酯肉豆蔻酸酯乙酸盐的非受体依赖性O2-产生，这表明蛋白激酶C激活后NADPH活性未受影响。粒细胞对f-MLP诱导的O2-产生的抑制作用取决于Yops的分泌，而不取决于YadA的表达。yopH基因的插入失活消除了人类粒细胞对抗体和补体调理的小肠结肠炎耶尔森菌的吞噬抑制作用，但并未消除粒细胞对f-MLP诱导的O2-产生或粒细胞蛋白酪氨酸磷酸化的抑制作用。这些发现表明，YopH的特定靶点不存在于f-MLP受体相关的信号转导中，并且涉及其他Yop介导的机制。
